Intercom systems for no-signal areas

Abstract

The present invention discloses an intercom system for a signal-free area. The present invention performs weighted calculation on the interference index, occupancy index and compatibility index of each frequency band to obtain the abnormal performance index of each frequency band at the time point of triggering a spectrum monitoring signal, selects the frequency band with a smaller abnormal performance index as the target frequency band, performs frequency adjustment according to the selected target frequency band, sends a frequency band switching signal to a signal acquisition module and a receiving module, comprehensively considers the interference index, occupancy index and compatibility index to evaluate the pros and cons of each frequency band, can select a frequency band that is more suitable for current communication needs, improves the reliability and efficiency of communication, and solves the problem in the prior art that the frequency band selection is not smart enough and the interference, occupancy and receiving sensitivity factors cannot be comprehensively considered, resulting in a high probability of selecting an unsuitable frequency band during selection, thereby affecting the communication quality.

Description

Technical Field

[0001] The invention relates to the technical field of intercoms, and in particular to an intercom system in a no-signal area. Background Art

[0002] In some special areas, such as outdoor exploration, mining operations or construction sites, there is often a lack of signal coverage. In these areas without signals, traditional communication equipment based on network signals cannot be used normally, and walkie-talkies have become an important communication tool.

[0003] However, the existing intercoms still have the following deficiencies when used in areas without signals:

[0004] The frequency band selection is not intelligent enough, and the interference, occupancy and receiving sensitivity factors cannot be comprehensively considered, resulting in a high probability of selecting an unsuitable frequency band, affecting the communication quality;

[0005] At the same time, when communication anomalies occur, there is a lack of effective feedback and processing mechanisms, and the causes of the anomalies cannot be promptly investigated and processed to restore communications, which limits the effectiveness and efficiency of the use of walkie-talkies in areas with no signals, and the degree of intelligence is low.

[0006] For this purpose, an intercom system for areas without signal is introduced. Summary of the invention

[0007] In view of this, the present invention provides an intercom system for a no-signal area to solve the problems raised by the above background technology.

[0008] The purpose of the present invention can be achieved by the following technical solution: an intercom system in a no-signal area, comprising:

[0009] Signal acquisition module: When a user uses the transmitter intercom in a signal-free area, the user's voice signal is collected and converted into an electrical signal. After the conversion is completed, the electrical signal is LDPC encoded;

[0010] Power control module: comprehensively evaluates the remaining battery power of the transmitter walkie-talkie at the current time point and the preset communication distance, so as to adjust the transmission power. After the adjustment is completed, the electrical signal is sent to the signal forwarding module;

[0011] Signal forwarding module: pre-processes the received electrical signal, triggers spectrum monitoring signaling immediately after the pre-processing is completed, and executes corresponding steps to select the target frequency band and switch it. After the switching is completed, the pre-processed electrical signal is sent to the receiving module according to the power adjusted by the power control module;

[0012] Receiving module: The receiving-end intercom receives the pre-processed electrical signal sent by the signal forwarding module and amplifies it. After amplification, it uses the LDPC decoding algorithm corresponding to the signal acquisition module to decode it and plays the decoded optimized signal;

[0013] Response feedback module: Set the reference threshold of the response time. When the receiving module receives the pre-processed electrical signal and does not get a response from the receiving intercom and the cumulative non-response time exceeds the set reference threshold, the abnormal signaling is triggered and the corresponding steps are executed.

[0014] In some embodiments, a comprehensive evaluation is performed on the remaining battery power of the transmitter walkie-talkie at the current time point and the preset communication distance, specifically:

[0015] The communication distance is converted into a distance influence index based on a preset conversion rule; three groups of distance value ranges corresponding to the preset communication distance are set; the three groups of distance value ranges are set to correspond to a distance influence index respectively; the preset communication distance is matched with each group of preset distance value ranges, so as to obtain the distance influence index corresponding to the current preset communication distance;

[0016] The remaining battery power is converted into a power impact index based on a preset conversion rule; three groups of power value ranges corresponding to the preset battery power are set; each group of power value ranges is set to correspond to a power impact index; the remaining battery power at a current time point is matched with the preset three groups of power value ranges, so as to obtain the power impact index corresponding to the remaining battery power at the current time point.

[0017] In some embodiments, the transmit power is adjusted, specifically:

[0018] The weight coefficients corresponding to the distance impact index and the power impact index are set respectively, and the distance impact index and the power impact index are multiplied by the corresponding weight coefficients respectively, and then the sum is calculated to obtain the power adjustment index;

[0019] The preset power adjustment index corresponds to each group of index value ranges, and each group of index value ranges is set to correspond to a group of transmission power adjustment ranges. The obtained power adjustment index is matched with the preset groups of index value ranges to obtain the transmission power adjustment range, and the transmission power is adjusted accordingly based on the adjustment range.

[0020] In some embodiments, spectrum monitoring signaling is triggered and corresponding steps are performed, specifically:

[0021] The monitored spectrum data is analyzed to determine the background noise power in the spectrum. For each signal in the monitored frequency band, its signal power is measured and the interference intensity index S is calculated from it, that is, through the formula ; Where P1, P2 and S represent the background noise power, the monitoring frequency band signal power and the interference intensity index respectively;

[0022] The interference intensity index S is converted into an intensity quantization value; each group of intensity value ranges corresponding to the interference intensity index is preset, and each group of intensity value ranges is set to correspond to an intensity quantization value; the interference intensity index of each frequency band is matched with each preset group of intensity value ranges, so as to obtain a corresponding intensity quantization value;

[0023] The interference signal type in each frequency band is identified, and the interference signal types include narrowband interference and broadband interference. The influence coefficients corresponding to narrowband interference and broadband interference are set respectively; the intensity quantization value of each frequency band is multiplied by the corresponding influence coefficient to obtain the interference index Qw of each frequency band.

[0024] In some embodiments, triggering spectrum monitoring signaling and executing corresponding steps further includes:

[0025] Obtain the occupancy ratio of each frequency band and convert the occupancy quantification value;

[0026] Preset the occupancy ratio corresponding to each group of ratio value ranges, and set each group of ratio value ranges to correspond to an occupancy quantization value; match the occupancy ratio of each frequency band with the preset group of ratio value ranges to obtain the corresponding occupancy quantization value; use the occupancy quantization value of each frequency band as the occupancy index Qe of each frequency band;

[0027] The receiving sensitivity of the receiving-end intercom in each frequency band is preset, and the compatible reference value is set for the frequency band with the highest receiving sensitivity; the ratio of the receiving sensitivity of each frequency band to the receiving sensitivity of the highest frequency band is calculated, that is, the receiving sensitivity of each frequency band / the receiving sensitivity of the highest frequency band is divided by the calculated ratio and the set compatible reference value, thereby obtaining the compatibility index Qr of each frequency band.

[0028] In some embodiments, the target frequency band is selected and switched, specifically:

[0029] According to the formula , the interference index Qw, occupancy index Qe and compatibility index Qr of each frequency band are weightedly calculated, so as to obtain the abnormal performance index QDF of each frequency band at the time point of triggering the spectrum monitoring signaling; wherein a1, a2 and a3 are the influence weight factors of the interference index Qw, occupancy index Qe and compatibility index Qr respectively;

[0030] A frequency band with a smaller abnormal performance index is selected as a target frequency band, and frequency adjustment is performed according to the selected target frequency band, and a frequency band switching signal is sent to the signal acquisition module and the receiving module.

[0031] In some embodiments, abnormal signaling is triggered and corresponding steps are performed, specifically:

[0032] S1: The pre-processed electrical signal is sent again through the signal forwarding module, and according to the set extension time, the reference threshold of the response time and the set extension time are accumulated as the extension reference threshold of the pre-processed electrical signal sent this time, and if the unresponse time of the pre-processed electrical signal sent this time exceeds the extension reference threshold, step S2 is executed;

[0033] S2: Send a test signal to the receiving module through the signal forwarding module. If the receiving module receives the test signal and gives feedback, execute step S3; if the receiving module receives the test signal but does not give feedback, it is determined that the communication chain is abnormal, and the determination result is sent to the technician;

[0034] S3: gradually increase the power according to the set power increase ratio, and resend the preprocessed electrical signal to the receiving module after each power increase until feedback is obtained. If no feedback is obtained, execute step S4.

[0035] In some embodiments, triggering abnormal signaling and executing corresponding steps further includes:

[0036] S4: After screening the currently switched frequency band, re-trigger the spectrum monitoring signaling and send it to the signal forwarding module, and switch according to the new target frequency band selected by the signal forwarding module. After switching the frequency band, first send the pre-processed electrical signal according to the power adjusted by the power control module, and wait for feedback from the receiving end intercom. If no feedback is received, execute step S3 again. If no feedback is received after executing step S3, execute step S5;

[0037] S5: Trigger emergency communication signaling and enable emergency communication mode.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The present invention performs weighted calculation on the interference index, occupancy index and compatibility index of each frequency band to obtain the abnormal performance index of each frequency band at the time point of triggering the spectrum monitoring signaling, selects the frequency band with the smaller abnormal performance index as the target frequency band, and performs frequency adjustment according to the selected target frequency band, and sends the frequency band switching signaling to the signal acquisition module and the receiving module, comprehensively considers the interference index, occupancy index and compatibility index to evaluate the advantages and disadvantages of each frequency band, can select a frequency band that is more suitable for the current communication needs, improves the reliability and efficiency of communication, and solves the problem that the frequency band selection in the prior art is not intelligent enough, and the interference, occupancy and receiving sensitivity factors cannot be comprehensively considered, resulting in a high probability of selecting an unsuitable frequency band during selection, which affects the communication quality;

[0040] When communication anomalies occur, the present invention performs feedback and processing through a series of steps, including resending signals, testing, adjusting power, reselecting frequency bands, etc., to restore communication as much as possible, and enables emergency communication mode when it cannot be restored, thus realizing an effective feedback and processing mechanism;

[0041] The present invention presets the value ranges of each group of indexes corresponding to the power adjustment index, sets each group of index value ranges to correspond to a group of adjustment ranges of the transmission power, matches the obtained power adjustment index with the preset value ranges of each group of indexes, thereby obtaining the adjustment range of the transmission power, and adjusts the transmission power accordingly based on the adjustment range. The transmission power is flexibly adjusted according to the communication distance and the battery power status, thereby improving the applicability and reliability of the walkie-talkie in various scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Further details, features and advantages of the present application are disclosed in the following description of exemplary embodiments in conjunction with the accompanying drawings, in which:

[0043] Figure 1 This is a principle block diagram of the present invention. DETAILED DESCRIPTION

[0044] Several embodiments of the present application will be described in more detail below with reference to the accompanying drawings so that those skilled in the art can implement the present application. The present application can be embodied in many different forms and purposes and should not be limited to the embodiments described herein. These embodiments are provided to make the present application comprehensive and complete, and to fully convey the scope of the present application to those skilled in the art. The embodiments do not limit the present application.

[0045] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this application belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the relevant art and / or the context of this specification, and will not be interpreted in an idealized or overly formal sense unless explicitly defined as such herein.

[0046] See also Figure 1 As shown, the intercom system in the no-signal area includes a signal acquisition module, a power control module, a signal forwarding module, a receiving module and a response feedback module;

[0047] The signal acquisition module is used to collect the user's voice signal and convert it into an electrical signal when the user uses the transmitter intercom in a signal-free area. After the conversion is completed, the electrical signal is LDPC encoded;

[0048] When a user uses a transmitter intercom in a signal-free area, the signal acquisition module first collects voice or data information; for example, when the user presses the voice call button, the microphone as the signal acquisition module starts to collect voice signals and converts them into electrical signals;

[0049] The power control module is used to comprehensively evaluate the remaining battery power of the transmitter walkie-talkie at the current time point and the preset communication distance, so as to adjust the transmission power, and after the adjustment is completed, send the electrical signal to the signal forwarding module;

[0050] Specifically:

[0051] The communication distance is converted into a distance impact index based on a preset conversion rule;

[0052] The preset communication distance corresponds to three groups of distance value ranges; the three groups of distance value ranges are specifically divided into a short distance range, a medium distance range and a long distance range; the three groups of distance value ranges are set to correspond to a distance influence index respectively; the preset communication distance is matched with each group of preset distance value ranges, so as to obtain the distance influence index corresponding to the current preset communication distance;

[0053] The longer the communication distance, the greater the distance impact index obtained by the corresponding matching;

[0054] Convert the remaining battery power into a power impact index based on a preset conversion rule;

[0055] Three groups of power value ranges corresponding to the preset battery power; the three groups of power value ranges are specifically divided into a sufficient power range, a medium power range and a low power range; each group of power value ranges is set to correspond to a power impact index; the remaining battery power at the current time point is matched with the preset three groups of power value ranges, so as to obtain the power impact index corresponding to the remaining battery power at the current time point;

[0056] The higher the remaining battery power is, the higher the corresponding power impact index is;

[0057] The above distance impact index range and power impact index range are both set to 1-10 and are integers;

[0058] The weight coefficients corresponding to the distance impact index and the power impact index are set respectively, and the distance impact index and the power impact index are multiplied by the corresponding weight coefficients respectively, and then the sum is calculated to obtain the power adjustment index;

[0059] Preset the index value ranges of each group corresponding to the power adjustment index, set each index value range to correspond to a set of transmit power adjustment ranges, match the obtained power adjustment index with the preset index value ranges of each group, thereby obtaining the transmit power adjustment range, and adjust the transmit power accordingly based on the adjustment range;

[0060] In summary, the transmission power is adjusted according to the communication distance and battery power status set by the user in advance. If the battery power is sufficient and the communication distance is far, the transmission power will be appropriately increased; for example, in different usage scenarios, such as outdoor exploration, mining operations or construction sites and other areas without signals, the communication distance and battery power may vary greatly. By flexibly adjusting the transmission power according to the specific distance and power status, the applicability and reliability of the walkie-talkie in various scenarios are improved;

[0061] For example,

[0062] In terms of communication distance, the preset short distance range is 0-1 km, and the corresponding distance impact index is 1; the medium distance range is 1-3 km, and the corresponding distance impact index is 5; the long distance range is above 3 km, and the corresponding distance impact index is 10; the preset communication distance is expected to be 4 km, then this communication distance belongs to the long distance range, and the matched distance impact index is 10.

[0063] The preset range of sufficient battery power is 80%-100% full power, and the corresponding power impact index is 10; the medium power range is 30%-80%, and the corresponding power impact index is 5; the low power range is 0-30%, and the corresponding power impact index is 1. If the remaining battery power of the walkie-talkie is 20% at this time, then this remaining battery power belongs to the low power range, and the matching power impact index is 1.

[0064] In terms of weight coefficients, it is assumed that the weight coefficient of the distance impact index is 0.6 and the weight coefficient of the power impact index is 0.4.

[0065] The power adjustment index is calculated by multiplying the distance impact index by the weight coefficient of 0.6 to get 6. The power impact index is 1, multiplied by the weight coefficient of 0.4 to get 0.4. The sum of the two gives a power adjustment index of 6.4.

[0066] The transmit power adjustment preset power adjustment index 0-3 corresponds to a transmit power adjustment range of reducing the current power to 30% of the initial setting power; the transmit power adjustment range 3-6 corresponds to maintaining the current power; the transmit power adjustment range 6-10 corresponds to increasing the current power to 150% of the initial setting within a safe range. Since the power adjustment index is 6.4, which falls within the range of 6-10, the transmit power will be increased to 150% of the initial setting within a safe range.

[0067] In summary, although the battery power is in the low power range, due to the long communication distance, after comprehensive evaluation, the transmission power is appropriately increased within the safe range. This takes into account both the needs of long-distance communication and the battery power situation, and makes reasonable use of battery energy while maintaining communication as much as possible;

[0068] The signal forwarding module is used to pre-process the received electrical signal, including filtering, denoising and other processing; after the pre-processing is completed, the spectrum monitoring signal is immediately triggered, and the corresponding steps are executed to select the target frequency band and switch it. After the switching is completed, the pre-processed electrical signal is sent to the receiving module according to the power adjusted by the power control module;

[0069] Specifically:

[0070] The monitored spectrum data is analyzed to determine the background noise power in the spectrum. For each signal in the monitored frequency band, its signal power is measured and the interference intensity index S is calculated from it, that is, through the formula ; Where P1, P2 and S represent the background noise power, the monitoring frequency band signal power and the interference intensity index respectively;

[0071] And convert the interference intensity index S into an intensity quantization value;

[0072] Preset the interference intensity index corresponding to each group of intensity value ranges, set each group of intensity value ranges to correspond to a strength quantization value; the range of the intensity quantization value is set to 1-5, and the higher the interference intensity index is, the higher the corresponding matched intensity quantization value is; match the interference intensity index of each frequency band with the preset groups of intensity value ranges to obtain the corresponding intensity quantization value;

[0073] Set different interference intensity levels. For example, when 3≥S>0, it is mild interference, quantized as 1; when 6≥S>3, it is moderate interference, quantized as 3; when S>6, it is severe interference, quantized as 5;

[0074] Identify the interference signal type in each frequency band, which includes narrowband interference and broadband interference, and set the corresponding influence coefficients of narrowband interference and broadband interference respectively;

[0075] Multiply the intensity quantization value of each frequency band by the corresponding influence coefficient to obtain the interference index Qw of each frequency band;

[0076] Obtain the occupancy ratio of each frequency band and convert the occupancy quantification value;

[0077] Preset the range of values ​​of each group of ratios corresponding to the occupancy ratio, and set each group of ratio ranges to correspond to an occupancy quantization value; the range of the occupancy quantization value is set to 1-5, and the higher the occupancy ratio, the higher the corresponding occupancy quantization value; match the occupancy ratio of each frequency band with the preset range of values ​​of each group of ratios, so as to obtain the corresponding occupancy quantization value; use the occupancy quantization value of each frequency band as the occupancy index Qe of each frequency band;

[0078] If the frequency band is occupied by a large number of devices (the occupation ratio exceeds 50%), the quantization value is 5; if it is occupied by a small number of devices (the occupation ratio is between 10% and 50%), the quantization value is 3; if there is basically no device occupying the frequency band (the occupation ratio is less than 10%), the quantization value is 1;

[0079] Preset the receiving sensitivity of the receiving end intercom in each frequency band, and set the compatible reference value for the frequency band with the highest receiving sensitivity; the compatible reference value is set to 5; calculate the ratio of the receiving sensitivity of each frequency band to the receiving sensitivity of the highest frequency band, that is, multiply the calculated ratio by the set compatible reference value through the receiving sensitivity of each frequency band / the receiving sensitivity of the highest frequency band, and thus obtain the compatibility index Qr of each frequency band;

[0080] According to the receiving sensitivity data of the receiving end walkie-talkie in each frequency band, the frequency band with the highest receiving sensitivity is quantified as 5. The receiving sensitivity of each frequency band is quantified according to the proportional relationship with the highest frequency band, and the compatibility index is calculated; for example, if the receiving sensitivity of a certain frequency band is 80% of the highest frequency band, the compatibility index Qe of the frequency band is 5×0.8=4; according to the formula , the interference index Qw, occupancy index Qe and compatibility index Qr of each frequency band are weightedly calculated, so as to obtain the abnormal performance index QDF of each frequency band at the time point of triggering the spectrum monitoring signaling; wherein a1, a2 and a3 are the influence weight factors of the interference index Qw, occupancy index Qe and compatibility index Qr respectively;

[0081] Select a frequency band with a smaller abnormal performance index as a target frequency band, perform frequency adjustment according to the selected target frequency band, and send a frequency band switching signal to the signal acquisition module and the receiving module;

[0082] Inform the transmitter and receiver that they will forward signals on the new frequency band;

[0083] By comprehensively considering the interference index, occupancy index and compatibility index, the pros and cons of each frequency band can be evaluated more comprehensively. Compared with considering only a single factor (such as only considering the interference situation or only considering the receiving sensitivity), this multi-factor evaluation can select a frequency band that is more suitable for current communication needs. For example, a frequency band may have less interference, but if it is occupied by a large number of devices or the receiving sensitivity of the receiving walkie-talkie in this frequency band is very low, then it may not be the best communication frequency band. By calculating the abnormal performance index, you can avoid selecting such a frequency band, thereby improving the reliability and efficiency of communication;

[0084] If the interference or occupancy of the frequency band or the receiving sensitivity of the receiving radio changes during the communication process, the above calculation and frequency band selection process can be repeated to switch to a more appropriate frequency band in time to ensure the continuity of communication quality;

[0085] The receiving module is used for the receiving-end intercom to receive the pre-processed electrical signal sent by the signal forwarding module and amplify it. After the amplification is completed, the LDPC decoding algorithm corresponding to the signal acquisition module is used for decoding, and the decoded optimized signal is played;

[0086] If it is a voice signal, it is played through the speaker, and if it is a data signal, it is displayed on the display screen;

[0087] The response feedback module is used to set a reference threshold of the response time. When the receiving module receives the pre-processed electrical signal and does not get a response from the receiving end intercom and the cumulative unresponsive time exceeds the set reference threshold, the abnormal signaling is triggered and the corresponding steps are executed;

[0088] Specifically:

[0089] S1: The pre-processed electrical signal is sent again through the signal forwarding module, and according to the set extension time, the reference threshold of the response time and the set extension time are accumulated as the extension reference threshold of the pre-processed electrical signal sent this time, and if the unresponse time of the pre-processed electrical signal sent this time exceeds the extension reference threshold, step S2 is executed;

[0090] S2: Send a test signal to the receiving module through the signal forwarding module. If the receiving module receives the test signal and gives feedback, execute step S3; if the receiving module receives the test signal but does not give feedback, it is determined that the communication chain is abnormal, and the determination result is sent to the technician;

[0091] S3: gradually increase the power according to the set power increase ratio, and resend the pre-processed electrical signal to the receiving module after each power increase until feedback is obtained. If no feedback is obtained, execute step S4;

[0092] Increase the power in certain steps (e.g. 1 dBm each time), resend the signal after each power increase and wait for the response from the receiving radio.

[0093] S4: After screening the currently switched frequency band, re-trigger the spectrum monitoring signaling and send it to the signal forwarding module, and switch according to the new target frequency band selected by the signal forwarding module. After switching the frequency band, first send the pre-processed electrical signal according to the power adjusted by the power control module, and wait for feedback from the receiving end intercom. If no feedback is received, execute step S3 again. If no feedback is received after executing step S3, execute step S5;

[0094] Re-perform spectrum monitoring and frequency band evaluation; although the target frequency band with the smallest abnormal performance index has been selected before, due to dynamic changes in the environment (such as the emergence of new interference sources, changes in frequency band occupancy, etc.), the frequency band is no longer suitable for communication;

[0095] S5: trigger emergency communication signaling and enable emergency communication mode;

[0096] The emergency communication mode may adopt a simpler and more interference-resistant signal transmission method, such as reducing the data transmission rate and using a simpler encoding method to improve the success rate of signal transmission;

[0097] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. Intercom system for no signal area, characterized by: include: Signal acquisition module: When a user uses the transmitter intercom in a signal-free area, the user's voice signal is collected and converted into an electrical signal. After the conversion is completed, the electrical signal is LDPC encoded; Power control module: comprehensively evaluates the remaining battery power of the transmitter walkie-talkie at the current time point and the preset communication distance, so as to adjust the transmission power. After the adjustment is completed, the electrical signal is sent to the signal forwarding module; Signal forwarding module: pre-processes the received electrical signal, triggers spectrum monitoring signaling immediately after the pre-processing is completed, and executes corresponding steps to select the target frequency band and switch it. After the switching is completed, the pre-processed electrical signal is sent to the receiving module according to the power adjusted by the power control module; Trigger the spectrum monitoring signaling and execute the corresponding steps, specifically analyzing the monitored spectrum data to determine the background noise power in the spectrum, measuring the signal power of each signal in the monitored frequency band, and calculating the interference intensity index S, that is, through the formula ; Where P1, P2 and S represent the background noise power, the monitoring frequency band signal power and the interference intensity index respectively; And convert the interference intensity index S into an intensity quantization value; Preset the interference intensity index corresponding to each group of intensity value ranges, set each group of intensity value ranges to correspond to a strength quantization value; match the interference intensity index of each frequency band with the preset groups of intensity value ranges, so as to obtain the corresponding strength quantization value; Identify the interference signal type in each frequency band, which includes narrowband interference and broadband interference, and set the corresponding influence coefficients of narrowband interference and broadband interference respectively; Multiply the intensity quantization value of each frequency band by the corresponding influence coefficient to obtain the interference index Qw of each frequency band; Obtain the occupancy ratio of each frequency band and convert the occupancy quantification value; Preset the occupancy ratio corresponding to each group of ratio value ranges, and set each group of ratio value ranges to correspond to an occupancy quantization value; Match the occupancy ratio of each frequency band with the preset value ranges of each group of ratios to obtain the corresponding occupancy quantization value; The quantified occupancy value of each frequency band is taken as the occupancy index Qe of each frequency band; Preset the receiving sensitivity of the receiving intercom in each frequency band, and set the compatible reference value for the frequency band with the highest receiving sensitivity; Calculate the ratio of the receiving sensitivity of each frequency band to the receiving sensitivity of the highest frequency band, that is, multiply the calculated ratio by the set compatibility reference value through the receiving sensitivity of each frequency band / the receiving sensitivity of the highest frequency band, thereby obtaining the compatibility index Qr of each frequency band; Select the target frequency band and switch it, specifically: According to the formula , the interference index Qw, occupancy index Qe and compatibility index Qr of each frequency band are weightedly calculated, so as to obtain the abnormal performance index QDF of each frequency band at the time point of triggering the spectrum monitoring signaling; wherein a1, a2 and a3 are the influence weight factors of the interference index Qw, occupancy index Qe and compatibility index Qr respectively; Select a frequency band with a smaller abnormal performance index as a target frequency band, perform frequency adjustment according to the selected target frequency band, and send a frequency band switching signal to the signal acquisition module and the receiving module; Receiving module: The receiving-end intercom receives the pre-processed electrical signal sent by the signal forwarding module and amplifies it. After amplification, it uses the LDPC decoding algorithm corresponding to the signal acquisition module to decode it and plays the decoded optimized signal; Response feedback module: Set the reference threshold of the response time. When the receiving module receives the pre-processed electrical signal and does not get a response from the receiving intercom and the cumulative non-response time exceeds the set reference threshold, the abnormal signaling is triggered and the corresponding steps are executed.

2. The intercom system for no-signal areas according to claim 1, characterized in that: Comprehensively evaluate the remaining battery power of the transmitter walkie-talkie at the current time point and the preset communication distance, specifically: The communication distance is converted into a distance influence index based on a preset conversion rule; three groups of distance value ranges corresponding to the preset communication distance are set; the three groups of distance value ranges are set to correspond to a distance influence index respectively; the preset communication distance is matched with each group of preset distance value ranges, so as to obtain the distance influence index corresponding to the current preset communication distance; Convert the remaining battery power into a power impact index based on a preset conversion rule; Three groups of power value ranges corresponding to the preset battery power; setting each group of power value ranges to correspond to a power impact index; matching the remaining battery power at the current time point with the preset three groups of power value ranges, thereby obtaining the power impact index corresponding to the remaining battery power at the current time point.

3. The intercom system for no-signal areas according to claim 2, characterized in that: Adjust the transmit power, specifically: The weight coefficients corresponding to the distance impact index and the power impact index are set respectively, and the distance impact index and the power impact index are multiplied by the corresponding weight coefficients respectively, and then the sum is calculated to obtain the power adjustment index; The preset power adjustment index corresponds to each group of index value ranges, and each group of index value ranges is set to correspond to a group of transmission power adjustment ranges. The obtained power adjustment index is matched with the preset groups of index value ranges to obtain the transmission power adjustment range, and the transmission power is adjusted accordingly based on the adjustment range.

4. The intercom system for no-signal areas according to claim 3, characterized in that: Trigger abnormal signaling and execute corresponding steps, specifically: S1: The pre-processed electrical signal is sent again through the signal forwarding module, and according to the set extension time, the reference threshold of the response time and the set extension time are accumulated as the extension reference threshold of the pre-processed electrical signal sent this time, and if the unresponse time of the pre-processed electrical signal sent this time exceeds the extension reference threshold, step S2 is executed; S2: Send a test signal to the receiving module through the signal forwarding module. If the receiving module receives the test signal and gives feedback, execute step S3; if the receiving module receives the test signal but does not give feedback, it is determined that the communication chain is abnormal, and the determination result is sent to the technician; S3: gradually increase the power according to the set power increase ratio, and resend the preprocessed electrical signal to the receiving module after each power increase until feedback is obtained. If no feedback is obtained, execute step S4.

5. The intercom system for no-signal areas according to claim 4, characterized in that: Triggering abnormal signaling and executing corresponding steps also includes: S4: After screening the currently switched frequency band, re-trigger the spectrum monitoring signaling and send it to the signal forwarding module, and switch according to the new target frequency band selected by the signal forwarding module. After switching the frequency band, first send the pre-processed electrical signal according to the power adjusted by the power control module, and wait for feedback from the receiving end intercom. If no feedback is received, execute step S3 again. If no feedback is received after executing step S3, execute step S5; S5: Trigger emergency communication signaling and enable emergency communication mode.

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